The new linear actuators excel when tough requirements for stability, lifetime, force and precision are paramount, making them suitable for applications in hard-to-access internals of instruments, where vibration cancellation and/or nanometer-realm adjustments are demanded. The PiezoWalk controller promotes long life by reducing the operating voltage on the piezo components to zero without affecting the entire holding force of up to 800 N (177 lbs).

Its piezoceramic shear and clamping components directly act on a moving runner coupled to the load. For long distance movements and maximum velocity, the runner is driven in full step mode, while constant velocity and extremely uniform movements are achieved using nanostepping mode. Aside from combining piezo-class precision with long travel ranges, the PiezoWalk drives also deliver a high-dynamics analog operation mode (100’s of Hz) in smaller distances (up to six µm).

Offered in a selection of two variants for closed- or open-loop operation, the N-216 linear motor are also available in two different load configurations. Its closed-loop variants feature a linear encoder for the moving runner’s direct position measurements. The encoder offers five nm resolution across the full travel range. Meanwhile, a position loop resolution of up to 30 picometers can be achieved during open-loop operation by using the analog operation mode.

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Unlike DC motors or flanges stepper with large screw ducts, the M-687 XY requires no additional installation space for its driver since the PILine piezoceramic linear motor is already integrated inside the stage. This feature allows easy integration of the stage in the microscope providing unhindered access to the specimen. The PILine motors keep the platform’s position stable by transmitting force directly to it while moving. By doing so, the motors do not produce additional heat.

PI’s stages closed-loop velocities can reach up to 250 mm/s. M-687’s settling behavior has been optimized to allow settling within a few milliseconds. Meanwhile, PI also acknowledges that slow movements are of great importance to users. Thus, the stage is specifically designed with 1000-fold magnification, which enables the microscope to cover movements even at a distance of a few micrometers per second.

Using a PILine drive together with a high-resolution position sensor produces high precision, still stage specifically designed to repeatedly reach positions with sub-micron accuracy. This is useful for imaging methods required for large specimen such as stitching and tiling.

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With velocities of up to 200mm/s, these drives are fast, compact and readily integrated.
In addition, PIline motors are self-locking at rest with zero heat generation, eliminating the need for an additional motor brake.
PI’s M-272 is a linear actuator designed for automation applications based on a maintenance-free PILine ultrasonic ceramic motor.
The M-272 closed-loop linear drive combines motor, actuator, linear encoder, guiding system and brake functionality in a very compact package.

Due to the integrated guiding system, a payload can be easily attached to the drive rod of the M-272 drive and positioned precisely.
The M-272 features a maintenance-free ceramic linear motor, has travel range of 50mm and 5um resolution with integrated linear encoder.
It is self-locking at rest, with no need for external brakes and no energy consumption.

PILine piezo motors are based on a new, patented, ultrasonic drive principle developed by PI.

Through its contact with the ceramic friction bar (runner), the moving part of the mechanical system is pushed along.

With each oscillatory cycle, the mechanical system executes a minute step of only a few nanometers and the macroscopic result is smooth motion with a virtually unlimited travel range.

The piezo ceramic plate is preloaded against the runner and thus generates the holding force when the drive is at rest.

Its highly specialized DSP handles all of the motion properties typical for ultrasonic piezomotors, such as dynamic control parameter adaption.
Optimized settling behavior of the mechanics within 10s of milliseconds is achieved by automatically switching between gain-sets for dynamic and static operation.

Physik Instrumente
www.physikinstrumente.com

Linear Motion Tips

The M-660 PILine® rotation stage allows high positioning speeds to 720 degrees /sec. It also features a very low profile of 15 mm (0.6") and a 35 mm Ø clear aperture

The M-660 stage reaches top speeds of 720 degrees/sec. and resolution to 40 µrad (8 arcsec). Its self-locking ceramic drive holds the position steady at rest, with no energy consumption and heat generation. A directly coupled precision optical encoder provides phase lag-free, backlash-free feedback to the servo controller.

Features & Advantages

* Max. Velocity 720 °/s, Unlimited Travel Range
* Low Profile: Only 15 mm (0.6”)
* Self-Locking Ceramic Direct Drive: Energy Saving & High Position Stability
* Direct Metrology Linear Encoder, 40 µrad Resolution (8 arcsecs)
* PILine® Drive: Non-Magnetic, Vacuum-Compatible Working Principle
* Compact Combinations with Linear Stages Available

The compact design with minimized mass and inertia provides high precision bidirectional speed and position control, as well as high speed motion contouring. The M-660 is based on the new U-164 Piezo Motor and outperforms the stability, acceleration and settling speed of traditional servo motor direct drives and gear-driven mechanisms. The innovative motor drive was also chosen by Leica Geosystems AG’s in their newest generation of surveying instruments for geodesy, because it can provide significantly higher speeds, shorter positioning times and a very high positioning accuracy when moving the measuring optics.

A newly designed piezo motor controller is available to take advantage of the specific motion characteristics of ultrasonic ceramic motors. USB interfacing and a solid software and driver package for seamless integration are included.

PI (Physik Instrumente) L.P.
www.physikinstrumente.com

Linear Motion Tips

The stages feature a piezo controller and comes with three, 24-bit digital interfaces (USB, TCP/IP, and RS-232) and a wide-band analog interface for compatibility with all control signals. With 24-bit DAC converters, commanded resolution is improved by two orders of magnitude over the still widely used 16-bit converters. The controller is also compatible with all major image acquisition packages and comes with a wide variety of software drivers and programming examples.

For highly stable, closed-loop operation, piezoresistive sensors are applied directly to the moving structure of the stage and precisely measure the displacement of the platform. The very high sensitivity of these sensors provides optimum position stability and responsiveness as well as sub-nanometer resolution. The proprietary servo circuit significantly improves the motion linearity compared to conventional piezoresistive sensor controllers.

For more information, email info@pi-usa.us.

www.pi-usa.us

Linear Motion Tips